/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.feilong.lib.net.ftp.parser;

import java.text.ParseException;

import com.feilong.lib.net.ftp.FTPClientConfig;
import com.feilong.lib.net.ftp.FTPFile;

/**
 * Implementation FTPFileEntryParser and FTPFileListParser for pre MacOS-X Systems.
 *
 * @version $Id$
 * @see com.feilong.lib.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
 * @since 3.1
 */
public class MacOsPeterFTPEntryParser extends ConfigurableFTPFileEntryParserImpl{

    static final String         DEFAULT_DATE_FORMAT        = "MMM d yyyy";                                              //Nov 9 2001

    static final String         DEFAULT_RECENT_DATE_FORMAT = "MMM d HH:mm";                                             //Nov 9 20:06

    /**
     * this is the regular expression used by this parser.
     *
     * Permissions:
     * r the file is readable
     * w the file is writable
     * x the file is executable
     * - the indicated permission is not granted
     * L mandatory locking occurs during access (the set-group-ID bit is
     * on and the group execution bit is off)
     * s the set-user-ID or set-group-ID bit is on, and the corresponding
     * user or group execution bit is also on
     * S undefined bit-state (the set-user-ID bit is on and the user
     * execution bit is off)
     * t the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and
     * execution is on
     * T the 1000 bit is turned on, and execution is off (undefined bit-
     * state)
     * e z/OS external link bit
     */
    private static final String REGEX                      = "([bcdelfmpSs-])"                                          // type (1)
                    + "(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?\\s+"                 // permission
                    + "(" + "(folder\\s+)" + "|" + "((\\d+)\\s+(\\d+)\\s+)"                                             // resource size & data size
                    + ")" + "(\\d+)\\s+"                                                                                // size
                                                                                                                        /*
                                                                                                                         * numeric or
                                                                                                                         * standard
                                                                                                                         * format date:
                                                                                                                         * yyyy-mm-dd
                                                                                                                         * (expecting hh:mm
                                                                                                                         * to
                                                                                                                         * follow)
                                                                                                                         * MMM [d]d
                                                                                                                         * [d]d MMM
                                                                                                                         * N.B. use
                                                                                                                         * non-space
                                                                                                                         * for MMM to allow
                                                                                                                         * for
                                                                                                                         * languages such as
                                                                                                                         * German which use
                                                                                                                         * diacritics (e.g.
                                                                                                                         * umlaut) in some
                                                                                                                         * abbreviations.
                                                                                                                         */
                    + "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S{3}\\s+\\d{1,2})|(?:\\d{1,2}\\s+\\S{3}))\\s+"
                                                                                                                        /*
                                                                                                                         * year (for
                                                                                                                         * non-recent
                                                                                                                         * standard format)
                                                                                                                         * -
                                                                                                                         * yyyy
                                                                                                                         * or time (for
                                                                                                                         * numeric
                                                                                                                         * or recent
                                                                                                                         * standard
                                                                                                                         * format) [h]h:mm
                                                                                                                         */
                    + "(\\d+(?::\\d+)?)\\s+"

                    + "(\\S*)(\\s*.*)";                                                                                 // the rest

    /**
     * The default constructor for a UnixFTPEntryParser object.
     *
     * @throws IllegalArgumentException
     *             Thrown if the regular expression is unparseable. Should not be seen
     *             under normal conditions. It it is seen, this is a sign that
     *             <code>REGEX</code> is not a valid regular expression.
     */
    public MacOsPeterFTPEntryParser(){
        this(null);
    }

    /**
     * This constructor allows the creation of a UnixFTPEntryParser object with
     * something other than the default configuration.
     *
     * @param config
     *            The {@link FTPClientConfig configuration} object used to
     *            configure this parser.
     * @throws IllegalArgumentException
     *             Thrown if the regular expression is unparseable. Should not be seen
     *             under normal conditions. It it is seen, this is a sign that
     *             <code>REGEX</code> is not a valid regular expression.
     * @since 1.4
     */
    public MacOsPeterFTPEntryParser(FTPClientConfig config){
        super(REGEX);
        configure(config);
    }

    /**
     * Parses a line of a unix (standard) FTP server file listing and converts
     * it into a usable format in the form of an <code> FTPFile </code>
     * instance. If the file listing line doesn't describe a file,
     * <code> null </code> is returned, otherwise a <code> FTPFile </code>
     * instance representing the files in the directory is returned.
     *
     * @param entry
     *            A line of text from the file listing
     * @return An FTPFile instance corresponding to the supplied entry
     */
    @Override
    public FTPFile parseFTPEntry(String entry){
        FTPFile file = new FTPFile();
        file.setRawListing(entry);
        int type;
        boolean isDevice = false;

        if (matches(entry)){
            String typeStr = group(1);
            String hardLinkCount = "0";
            String usr = null;
            String grp = null;
            String filesize = group(20);
            String datestr = group(21) + " " + group(22);
            String name = group(23);
            String endtoken = group(24);

            try{
                file.setTimestamp(super.parseTimestamp(datestr));
            }catch (ParseException e){
                // intentionally do nothing
            }

            // A 'whiteout' file is an ARTIFICIAL entry in any of several types of
            // 'translucent' filesystems, of which a 'union' filesystem is one.

            // bcdelfmpSs-
            switch (typeStr.charAt(0)) {
                case 'd':
                    type = FTPFile.DIRECTORY_TYPE;
                    break;
                case 'e': // NET-39 => z/OS external link
                    type = FTPFile.SYMBOLIC_LINK_TYPE;
                    break;
                case 'l':
                    type = FTPFile.SYMBOLIC_LINK_TYPE;
                    break;
                case 'b':
                case 'c':
                    isDevice = true;
                    type = FTPFile.FILE_TYPE; // TODO change this if DEVICE_TYPE implemented
                    break;
                case 'f':
                case '-':
                    type = FTPFile.FILE_TYPE;
                    break;
                default: // e.g. ? and w = whiteout
                    type = FTPFile.UNKNOWN_TYPE;
            }

            file.setType(type);

            int g = 4;
            for (int access = 0; access < 3; access++, g += 4){
                // Use != '-' to avoid having to check for suid and sticky bits
                file.setPermission(access, FTPFile.READ_PERMISSION, (!group(g).equals("-")));
                file.setPermission(access, FTPFile.WRITE_PERMISSION, (!group(g + 1).equals("-")));

                String execPerm = group(g + 2);
                if (!execPerm.equals("-") && !Character.isUpperCase(execPerm.charAt(0))){
                    file.setPermission(access, FTPFile.EXECUTE_PERMISSION, true);
                }else{
                    file.setPermission(access, FTPFile.EXECUTE_PERMISSION, false);
                }
            }

            if (!isDevice){
                try{
                    file.setHardLinkCount(Integer.parseInt(hardLinkCount));
                }catch (NumberFormatException e){
                    // intentionally do nothing
                }
            }

            file.setUser(usr);
            file.setGroup(grp);

            try{
                file.setSize(Long.parseLong(filesize));
            }catch (NumberFormatException e){
                // intentionally do nothing
            }

            if (null == endtoken){
                file.setName(name);
            }else{
                // oddball cases like symbolic links, file names
                // with spaces in them.
                name += endtoken;
                if (type == FTPFile.SYMBOLIC_LINK_TYPE){

                    int end = name.indexOf(" -> ");
                    // Give up if no link indicator is present
                    if (end == -1){
                        file.setName(name);
                    }else{
                        file.setName(name.substring(0, end));
                        file.setLink(name.substring(end + 4));
                    }

                }else{
                    file.setName(name);
                }
            }
            return file;
        }
        return null;
    }

    /**
     * Defines a default configuration to be used when this class is
     * instantiated without a {@link FTPClientConfig FTPClientConfig}
     * parameter being specified.
     * 
     * @return the default configuration for this parser.
     */
    @Override
    protected FTPClientConfig getDefaultConfiguration(){
        return new FTPClientConfig(FTPClientConfig.SYST_UNIX, DEFAULT_DATE_FORMAT, DEFAULT_RECENT_DATE_FORMAT);
    }

}
